usr.bin/tset/term.c

   1 /*-
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#)term.c   8.1 (Berkeley) 6/9/93
  34  * $FreeBSD: src/usr.bin/tset/term.c,v 1.4 1999/08/28 01:06:58 peter Exp $
  35  * $DragonFly: src/usr.bin/tset/term.c,v 1.4 2004/08/30 18:06:50 eirikn Exp $
  36  */
  37
  38 #include <sys/types.h>
  39 #include <err.h>
  40 #include <errno.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <unistd.h>
  45 #include <ttyent.h>
  46 #include "extern.h"
  47
  48 char    tbuf[1024];                     /* Termcap entry. */
  49
  50 const char *askuser(const char *);
  51 char    *ttys(char *);
  52
  53 /*
  54  * Figure out what kind of terminal we're dealing with, and then read in
  55  * its termcap entry.
  56  */
  57 const char *
  58 get_termcap_entry(char *userarg, char **tcapbufp)
  59 {
  60         struct ttyent *t;
  61         int rval;
  62         char *p, *ttypath;
  63         const char *ttype;
  64
  65         if (userarg) {
  66                 ttype = userarg;
  67                 goto found;
  68         }
  69
  70         /* Try the environment. */
  71         if ((ttype = getenv("TERM")))
  72                 goto map;
  73
  74         /* Try ttyname(3); check for dialup or other mapping. */
  75         if ((ttypath = ttyname(STDERR_FILENO))) {
  76                 if ((p = strrchr(ttypath, '/')))
  77                         ++p;
  78                 else
  79                         p = ttypath;
  80                 if ((t = getttynam(p))) {
  81                         ttype = t->ty_type;
  82                         goto map;
  83                 }
  84         }
  85
  86         /* If still undefined, use "unknown". */
  87         ttype = "unknown";
  88
  89 map:    ttype = mapped(ttype);
  90
  91         /*
  92          * If not a path, remove TERMCAP from the environment so we get a
  93          * real entry from /etc/termcap.  This prevents us from being fooled
  94          * by out of date stuff in the environment.
  95          */
  96 found:  if ((p = getenv("TERMCAP")) != NULL && *p != '/')
  97                 unsetenv("TERMCAP");
  98
  99         /*
 100          * ttype now contains a pointer to the type of the terminal.
 101          * If the first character is '?', ask the user.
 102          */
 103         if (ttype[0] == '?') {
 104                 if (ttype[1] != '\0')
 105                         ttype = askuser(ttype + 1);
 106                 else
 107                         ttype = askuser(NULL);
 108         }
 109
 110         /* Find the termcap entry.  If it doesn't exist, ask the user. */
 111         while ((rval = tgetent(tbuf, ttype)) == 0) {
 112                 warnx("terminal type %s is unknown", ttype);
 113                 ttype = askuser(NULL);
 114         }
 115         if (rval == -1)
 116                 errx(1, "termcap: %s", strerror(errno ? errno : ENOENT));
 117         *tcapbufp = tbuf;
 118         return (ttype);
 119 }
 120
 121 /* Prompt the user for a terminal type. */
 122 const char *
 123 askuser(const char *dflt)
 124 {
 125         static char answer[256];
 126         char *p;
 127
 128         /* We can get recalled; if so, don't continue uselessly. */
 129         if (feof(stdin) || ferror(stdin)) {
 130                 (void)fprintf(stderr, "\n");
 131                 exit(1);
 132         }
 133         for (;;) {
 134                 if (dflt)
 135                         (void)fprintf(stderr, "Terminal type? [%s] ", dflt);
 136                 else
 137                         (void)fprintf(stderr, "Terminal type? ");
 138                 (void)fflush(stderr);
 139
 140                 if (fgets(answer, sizeof(answer), stdin) == NULL) {
 141                         if (dflt == NULL) {
 142                                 (void)fprintf(stderr, "\n");
 143                                 exit(1);
 144                         }
 145                         return (dflt);
 146                 }
 147
 148                 if ((p = strchr(answer, '\n')))
 149                         *p = '\0';
 150                 if (answer[0])
 151                         return (answer);
 152                 if (dflt != NULL)
 153                         return (dflt);
 154         }
 155 }